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THE STOCHASTIC ESTIMATION OF SATELLITE CLOCK CORRECTION INFORMATION IN WADGPS

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Geo-Spatial Information Science 2000年第1期3卷 66-69页

作者： Hseyin Bki iz GE Maorong Esmond Mok

Using autocorrelation information of the pseudorange errors generated by se- lective availability (SA) frequency dithering, we have constructed a simple first order stochas- tic model for SA effects. This model has been used in a Kalman filter to account for the stochastic behavior of SA dithering in estimating satellite clock information in wide area dif- ferential GPS. We have obtained fifteen percent improvement in the user positioning using the correlation information on the satellite clock information in a Kalman filter, when comparing the results obtained using a regular least square estimation.

关键词： stochastic model wide area differential GPS(WADGPS) selective availability

Characterization by EBSD of Antimony-calcium Rich Phases Formed during Purification of Aluminum Scrap

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Journal of Wuhan University of Technology(Materials Science) 2013年第4期28卷 647-649页

作者： MUiz Rodrigo FLORES Alfredo ORTiz Juan RODRíGUEZ Nelly MARTíNEZ Fernando LUNA Jesús OROZCO Pilar Faculty of Engineering Autonomous University of Coahuila Camporedondo Unit CINVESTAV Saltillo Unit Department of Metal Mechanics Technological Institute of Saltillo Faculty of Engineering Autonomous University of Zacatecas

We studied the influence of antimony on the modification rate of the silicon eutectic with sodium and/or strontium for castiig of A1-Si alloys, and introduced controlled Ca and Sb to the system and studied the resulting compounds, which were determined to be CazSb and A1Sb. Scanning electron microscopy together with the complementary technique of electron backscatter diffraction （EBSD） were used to characterize the materials. The experimental results provided the basis for us to establish that antimony removal from AI occurs mainly through the reaction （Sb）A1 ＋ 2Ca = Ca^Sb ＋ A1.

关键词： aluminum alloys antimony contamination modification

Incorporation of dysprosium ions into PbTiO_(3) ferroelectric ceramic system

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Journal of Advanced Dielectrics 2015年第1期5卷 29-33页

作者： A.Peláiz-Barranco Y.Mendez-González Jinfei Wang Tongqing Yang Facultad de Física-IMRE Universidad de La Habana.San Lázaro y L Vedado.La Habana 10400Cuba Functional Materials Research Laboratory College for Materials Science and Engineering Tongji University 4800 CaoanShanghai 201804P.R.China

A structural analysis concerning the incorporation of dysprosium into A-and/or B-sites of the lead titanate is *** two"boundary"refinements are presented,i.e.,Dy^(2+)substitutes for Pb^(2+)(Dy^(3+)substitutes for Ti^(4+))and Dy^(3+)substitutes for Pb^(2+)(Dy^(3+)substitutes for Ti^(4+)).The results offer quantitative information about the incorporation into both crystallographic *** increase of Dy^(3+)fraction into B-site provides the increase of the Ti^(4+)atomic displacement along the[001]direction and the tetragonal distortion.

关键词： Lead titanate lanthanides perovskites crystalline structure

Systematic Approach for Web Protection Runtime Tools’Effectiveness Analysis

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Computer Modeling in Engineering & Sciences 2022年第12期133卷 579-599页

作者： Tomás Sureda Riera Juan Ramón Bermejo Higuera Javier Bermejo Higuera Juan Antonio Sicilia Montalvo José Javier Martínez Herráiz Computer Science Department University of AlcaláMadrid28801Spain Escuela Superior de Ingeniería y Tecnología Universidad Internacional de La RiojaLogrono26006Spain

Web applications represent one of the principal vehicles by which attackers gain access to an orga.ization’s network or ***,different approaches to protect web applications have been proposed to *** them,the two major approaches are Web Application Firewalls(WAF)and Runtime Application Self Protection(RASP).It is,thus,essential to understand the differences and relative effectiveness of both these approaches for effective decisionmaking regarding the security of web *** we present a comparative study between WAF and RASP simulated settings,with the aim to compare their effectiveness and efficiency against different categories of *** this,we used computation of different metrics and sorted their results using F-Score *** found that RASP tools scored better than WAF *** this study,we also developed a new experimental methodology for the objective evaluation ofweb protection tools since,to the best of our knowledge,nomethod specifically evaluates web protection tools.

关键词： Web Application Firewall(WAF) Runtime Application Self Protection(RASP) F-Score web attacks experimental methodology

Microstructural Feature of As-cast A-356 Alloy Modifiers with the Addition of SrO

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Journal of Wuhan University of Technology(Materials Science) 2014年第3期29卷 617-619页

作者： MU?iz Rodrigo FLORES Alfredo ORTiz Juan RODRíGUEZ Nelly MARTíNEZ Fernando OROZCO Pilar LUNA Jesús Equihua Fabián García Adrián Faculty of Engineering Autonomous University of Coahuila Camporedondo UnitSaltillo Coahuila México CINVESTAV Saltillo Unit Department of Metal Mechanics Technological Institute of Saltillo Faculty of Engineering Autonomous University of Zacatecas FIME Autonomous University of Coahuila Unit

To explore the effect of strontium on the structure of as-cast A356 alloy, the strontium was incorporated to the alloy by metallothermic reduction of SrO where the mineral was added to the melt through the submerged powders injection technique. The evaluation of the modification of the eutectie silicon and the chemical analysis of samples were done using optical microscopy （OP） and inductively coupled plasma （ICP）, respectively, while microstructural analyses by scanning electron microscopy （SEM）, and the injection time was variable. Magnesium was added to the melt to increase the reactivity and reduce the surface tension of the molten aluminum. It was possible to increase the strontium content from 0 to 0.027% after 20 minutes treatment. This concentration was sufficient to bring about full modification structure of eutectic silicon of as cast alloy A 356 and the acceptable quality metallurgical of alloy.

关键词： modification microstmcture strontium eutectic silicon submerged powder injection

Structural,microstructural and dielectric characterizations of(Bi_(0.5)Na_(0.5))TiO_(3) based lead-free ferroelectric ceramics

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Journal of Advanced Dielectrics 2021年第3期11卷 39-44页

作者： B.R.Moya A.C.Silva A.Peláiz-Barranco J.D.S.Guerra Grupo de Ferroelétricos e Materiais Multifuncionais Instituto de Física Universidade Federal de Uberlandia UberlandiaMinas Gerais 38408-100Brazil Departamento de Física e Química UNESP Campus de Ilha SolteiraSao Paulo 15385-000Brazil Grupo de Materiales Ferroicos Facultad de Física-Instituto de Ciencia y Tecnología de Materiales Universidad de La Habana La Habana 10400Cuba

(1-x)(Bi_(0.5)Na_(0.5))TiO_(3)-xBaTiO_(3) lead-free ceramics have been obtained from the conventional solid-state reaction sintering *** structural properties were investigated from X-ray diffraction and Raman spectroscopy *** revealed well-crystallized ceramic samples with perovskite *** properties,obtained from scanning electron microscopy measurements,have shown high density with very low porosity *** dielectric response,analyzed as a function of the temperature and several frequencies,showed very broad peaks with a strong frequency dependence of the temperature for the maximum dielectric permittivity for the modified *** were analyzed considering the influence of the BaTiO3 content on the studied physical properties.

关键词： Lead-free BNT Raman spectroscopy dielectric response

Effect of Carbon Graphite on the Crystallization of Andalusite: Application to the Synthesis of Mullite and the Improvement of Refractory Quality

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Materials Sciences and Applications 2013年第6期4卷 337-346页

作者： Chaouki Sadik iz-Eddine El Amrani Abderrahman Albizane Department of Chemistry Faculty of Science and Technology University Hassan II Mohammedia-Casablanca Morocco Department of Earth Sciences Scientific Institute University Mohammed V Agdal Rabat Morocco

Different mixtures of Moroccan silica-alumina geomaterials were used for the preparation of refractory ceramics. A formula of composition (M2) has allowed obtaining a good quality of refractory. Addition of a small quantity of carbon (1%) to the M2 formula has substantially improved the quality of the refractory. The morphological, textural and mineralogical evolution, through SEM and XRD shows that the addition of carbon, which plays a catalytic role, favors the crystallization of andalusite. Then, from 1200°C, the andalusite starts to transform to primary mullite needles. At 1400°C, the mullite becomes the major mineral phase beside cristobalite and vitreous phase.

关键词： Refractory Alumina-Silica Andalusite Mullite Morocco

Cerium extraction by metallothermic reduction using cerium oxide powder injection

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Journal of Rare Earths 2011年第1期29卷 74-76页

作者： J.S.Luna A A.Flores V R.Muiz V A.F.Fuentes J.Torres N.Rodríguez R J.C.Ortiz P.Orozco CINVESTAV Unidad Saltillo Saltillo-Monterrey Highway Km.13.5P.O.Box 66325000SaltilloCoahuilaMéxico Faculty of Engineering Autonomous Univer-sity of CoahuilaCamporedondo UnitSaltilloCoahuilaMéxico Department of Metal Mechanics Technological Institute of SaltilloV.Carranza Blvd 2400SaltilloCoahuilaZC 25280México Academic Unit of Engineering Autonomous University of CoahuilaLopez Velarde Av.ZacatecasZac.ZC 98060

This work presented the feasibility of cerium recovery by Al-Mg alloy through the metallothermic reduction of CeO2 to obtain a master alloy Al-4%Ce. The master alloy obtained in this investigation was for the grain refinement and modification of Al-Si alloys. The reagent was incorporated into a molten alloy using the submerged powder injection technique, and metallic samples were obtained during injection. Chemical and microstructural analyses （by inductively coupled plasma （ICP） and scanning electron microscopy （SEM）, respectively） confirmed the possibility of Ce uptake in the bath （0 to 4 wt.%）, as CeO2 was reduced through metallothermic reactions in the molten alloys. Based on the characterization of reaction products, the sequence of the reaction was proposed.

关键词： cerium recovery metallothermic reduction reaction products rare earths

Composition and Refractory Properties of Mixtures of Moroccan Silica-Alumina Geomaterials and Alumina

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New Journal of Glass and Ceramics 2013年第2期3卷 59-66页

作者： Chaouki Sadik iz-Edinne El Amrani Abderahman Albizane Department of Chemistry Faculty of Science and Technology University Hassan II Mohammedia Casablanca Morocco Department of Earth Sciences Geo-Materials and Geo-Environment Team (Geo M&E) Scientific Institute University Mohammed V Agdal Rabat Morocco

Five mixtures (M1 to M5) of silica-alumina geomaterials and two varieties of alumina (AP and AR) were used for the elaboration of mullite refractory materials between 1500℃ and 1600℃. An X-ray diffraction (XRD) analysis showed that the refractory samples are composed of mullite, corundum and silica. The length of the mullite crystals was measured by a method of image analysis of scanning electron microscopy (SEM). Chemical and mechanical properties of these materials were investigated and correlated with their microstructure. Resistance towards Acid Attack test showed that the refractory samples present good resistance, as well as, the alumina powder AR obtained from waste of silica-alumina bricks proves to be efficient for an eventual use.

关键词： Clay Silica-Alumina Mullite Refractory Mechanical Properties